1. Field of the Invention
The present invention relates to a process for producing a cycloalkanone oxime by the ammoximation reaction of a cycloalkanone. Cycloalkanone oximes are useful as raw materials for lactams and the like.
2. Description of the Related Art
A process for producing a cycloalkanone oxime includes an ammoximation reaction of a cycloalkanone with hydrogen peroxide and ammonia in the presence of a titanosilicate catalyst (see, for example, U.S. Pat. Nos. 4,745,221, 4,794,198, 5,312,987, 5,227,525, 6,828,459, and U.S. 2004/204609 A). The ammoximation reaction is advantageously carried out in a continuous method in view of productivity or operationality, and usually carried out in an organic solvent as a reaction solvent.
For example, U.S. Pat. No. 4,794,198 discloses a continuous ammoximation reaction of a cyclohexanone using t-butyl alcohol in an amount of from 0.1 to 100 times by mole, preferably from 0.5 to 10 times by mole of the cyclohexanone at from 60° C. to 120° C., and specifically it discloses a reaction using t-butyl alcohol in an amount of 2.1 times by weight of cyclohexanone at 83° C. and a reaction using t-butyl alcohol in an amount of 3.2 or more times by weight of cyclohexanone at 80° C.
U.S. Pat. No. 5,312,987 and U.S. Pat. No. 5,227,525 disclose a continuous ammoximation reaction of a carbonyl compound such as a cycloalkanone using an organic solvent in an amount of from 2.5 to 10 times by weight of the carbonyl compound at from 60° C. to 100° C., preferably at from 70° C. to 90° C., and specifically they disclose a continuous ammoximation reaction of cyclohexanone using t-butyl alcohol in an amount of 2.9 or more times by weight of cyclohexanone at 85° C.
Moreover, U.S. Pat. No. 6,828,459, and U.S. 2004/204609 A disclose a continuous ammoximation reaction of cyclohexanone using an organic solvent at from 50° C. to 100° C., and specifically they disclose a reaction using t-butyl alcohol in an amount of 3.3 times by weight of cyclohexanone at 85° C.